Ye Olde Rocket Forum

Go Back   Ye Olde Rocket Forum > The Golden Age of Model Rocketry > Model Rocket History
User Name
Password
Auctions Register FAQ Members List Calendar Today's Posts Search Mark Forums Read


Reply
 
Thread Tools Search this Thread Display Modes
  #41  
Old 02-25-2017, 03:05 PM
ghrocketman's Avatar
ghrocketman ghrocketman is offline
President, MAYHEM AGITATORS, Inc.
 
Join Date: Jul 2005
Location: Nunya Bizznuss, Michigan
Posts: 13,443
Default

How did I not anticipate a certain someone chiming in claiming they were somehow a copy of something related to a U.S. Rockets product that has been OOP for even way longer ?
__________________
When in doubt, WHACK the GAS and DITCH the brake !!!

Yes, there is such a thing as NORMAL
, if you have to ask what is "NORMAL" , you probably aren't !

Failure may not be an OPTION, but it is ALWAYS a POSSIBILITY.
ALL systems are GO for MAYHEM, CHAOS, and HAVOC !
Reply With Quote
  #42  
Old 02-25-2017, 06:04 PM
Doug Sams's Avatar
Doug Sams Doug Sams is offline
Old Far...er...Rocketeer
 
Join Date: Mar 2005
Location: Plano, TX resident since 1998.
Posts: 3,965
Default

Quote:
Originally Posted by ManofSteele
We had no failures in the last 11,000 we fired...
Quote:
Originally Posted by neil_w
That's pretty darn impressive.
I agree. I've seen production in the millions of units, on devices where the volume consumed in qualification was a fraction of 11,000 .

The North Coast motors appear to have been very well vetted

Doug

.
__________________
YORF member #11
Reply With Quote
  #43  
Old 02-26-2017, 10:16 AM
Jerry Irvine's Avatar
Jerry Irvine Jerry Irvine is offline
Freeform rocketry advocate.
 
Join Date: Jan 2008
Location: Claremont, CA "The intellectual capitol of the world."-WSJ
Posts: 3,780
Default

Quote:
Originally Posted by ghrocketman
How did I not anticipate a certain someone chiming in claiming they were somehow a copy of something related to a U.S. Rockets product that has been OOP for even way longer ?
Noting historical fact is not an attack of any kind.

I will note that while the grain geometry was a precise copy of mine, as were some of the earliest NCR kits (Pearson version not NCRBE), it is also true the casing system for the Dark Star motors was an engineering masterpiece and clearly unique and innovative. The material selection(s) are superior to the Aerotech SU molded cases in several respects, probably because of Scott's materials expertise and a higher budget for molding than AT has. The motor "system" as a whole was unique. special, reliable, and for a time widely available. A short time. If Matt can't share how many were shipped, perhaps he can share how many months they shipped. I would also be curious about the operating pressure of the motor.

The U.S. Rockets F40 and F80 (same geometry and casing system different propellants) was available from about 1987-1993 so I suspect about as many were sold in total but without the Estes figures being disclosed even this many years later, it is hard to compare accurately. They operated at about 400 psi.

Last edited by Jerry Irvine : 02-26-2017 at 11:25 AM.
Reply With Quote
  #44  
Old 02-26-2017, 10:33 AM
tbzep's Avatar
tbzep tbzep is offline
Dazed and Confused
 
Join Date: Mar 2005
Location: TN
Posts: 11,610
Default

Grain geometry is not a copy, at least not of your products. You both used the proper proportion of length/diameter/core for your Bates grain with the motor diameter being the driving factor of the other measurements. If the geometry is off, you get spikes where you don't want them, burn throughs, etc. Those numbers have been around longer than either you or Dixon have been making motors.
__________________
I love sanding.
Reply With Quote
  #45  
Old 02-26-2017, 11:28 AM
Jerry Irvine's Avatar
Jerry Irvine Jerry Irvine is offline
Freeform rocketry advocate.
 
Join Date: Jan 2008
Location: Claremont, CA "The intellectual capitol of the world."-WSJ
Posts: 3,780
Default

Quote:
Originally Posted by tbzep
Grain geometry is not a copy, at least not of your products. You both used the proper proportion of length/diameter/core for your Bates grain with the motor diameter being the driving factor of the other measurements. If the geometry is off, you get spikes where you don't want them, burn throughs, etc. Those numbers have been around longer than either you or Dixon have been making motors.
You will note that virtually every motor ever made has a BATES ratio somewhere near 1.7. Those produce a somewhat flat trace thus is more power efficient. Check your AT reloads and CTI reloads and check aspect ratios. The 1.25" long grain produces a regressive trace. The 38mm and 29mm reloads from AT are sized to match shipping mass restrictions.

If this subject interests you I have posted considerable tech data here:

http://v-serv.com/usr/custom/rr38mmCUSTOM.htm

Tech Jerry
Reply With Quote
  #46  
Old 02-26-2017, 11:34 AM
tbzep's Avatar
tbzep tbzep is offline
Dazed and Confused
 
Join Date: Mar 2005
Location: TN
Posts: 11,610
Default

Quote:
Originally Posted by Jerry Irvine
You will note that virtually every motor ever made has a BATES ratio somewhere near 1.7. Those produce a somewhat flat trace thus is more power efficient. Check your AT reloads and CTI reloads and check aspect ratios. The 1.25" long grain produces a regressive trace. The 38mm and 29mm reloads from AT are sized to match shipping mass restrictions.

I pretty much just said that.
__________________
I love sanding.
Reply With Quote
  #47  
Old 02-28-2017, 09:33 PM
ManofSteele ManofSteele is offline
Level 5 Certified
 
Join Date: Mar 2005
Location: Sandy, UT
Posts: 206
Default

Quote:
Originally Posted by Jerry Irvine
Noting historical fact is not an attack of any kind.

I would also be curious about the operating pressure of the motor.
.


I didn't take it as an attack, Jerry. it indeed was a historical fact.

While others had some issues with Jerry over the years, he and I have had a cordial, respectful relationship. We had a lot of fun parked next to each other at one of the Colorado LDRS launches when I was working for Estes.

We ran the motors at a target pressure of 400 psi at 70 degrees F. That gave a good balance of delivered Isp with lots of safety margin on the case design.

Matt
Reply With Quote
  #48  
Old 03-01-2017, 06:55 AM
Jerry Irvine's Avatar
Jerry Irvine Jerry Irvine is offline
Freeform rocketry advocate.
 
Join Date: Jan 2008
Location: Claremont, CA "The intellectual capitol of the world."-WSJ
Posts: 3,780
Default

I generally do not direct my posts at an individual even if I quote a particular post. I tend to post to the group as a whole. I have no dispute with anyone here. But the folks with whom I do have a dispute tend to avoid where I dwell because I bring up historical fact that is uncomfortable for them. Pretty sure that is why I was banned from TRF! It certainly is why my posts were deleted when someone bought RocketryOnline.com. Even I can't imagine how labor intensive that was!

Last edited by Jerry Irvine : 03-01-2017 at 07:24 AM.
Reply With Quote
  #49  
Old 03-04-2017, 07:29 PM
Initiator001 Initiator001 is offline
Too Many Initiators is Never Enough
 
Join Date: Mar 2005
Location: San Diego, CA
Posts: 2,394
Default Pictures!

For those who never had the chance to fly or see Dark Star F62 motors flown, here are some pictures of NCRBE kits flown with F62 motors.
Attached Thumbnails
Click image for larger version

Name:  NCRBE Big Brute F62-4 DART Launch  1997.jpg
Views: 43
Size:  20.7 KB  Click image for larger version

Name:  NCRBE Eliminator F62-6 NARAM-39  1997.jpg
Views: 54
Size:  27.0 KB  Click image for larger version

Name:  NCRBE Phantom 4000 F62-4 DART Launch 1997.jpg
Views: 40
Size:  23.1 KB  Click image for larger version

Name:  DSF62-001 NCRBE Phantom 4000.jpg
Views: 54
Size:  97.7 KB  Click image for larger version

Name:  NCRBE Lance Beta II F62-6 NARAM-42  2000.jpg
Views: 42
Size:  19.3 KB  
__________________
Bob
S.A.M. # 0014
Reply With Quote
  #50  
Old 03-04-2017, 07:40 PM
Earl's Avatar
Earl Earl is offline
Apollo Nut
 
Join Date: Dec 2006
Posts: 4,893
Default

Quote:
Originally Posted by Initiator001
For those who never had the chance to fly or see Dark Star F62 motors flown, here are some pictures of NCRBE kits flown with F62 motors.


One can very much see the Scott Dixon influence a la the Vulcan 'Smokey Sam' black smoke density. Loved those Vulcan motors. Scott did great work on his motors. Don't think I ever had a failure with Vulcan motors and back in the day I flew quite a number of them.

Nice launch photos!

Earl
__________________
Earl L. Cagle, Jr.
NAR# 29523
TRA# 962
SAM# 73
Owner/Producer
Point 39 Productions

Rocket-Brained Since 1970
Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump



All times are GMT -5. The time now is 04:57 AM.


Powered by: vBulletin Version 3.0.7
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Ye Olde Rocket Shoppe © 1998-2024